userlibandfileserver/fileserver/sfile/sf_cache_man.cpp
changeset 0 a41df078684a
child 41 0ffb4e86fcc9
equal deleted inserted replaced
-1:000000000000 0:a41df078684a
       
     1 // Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies).
       
     2 // All rights reserved.
       
     3 // This component and the accompanying materials are made available
       
     4 // under the terms of the License "Eclipse Public License v1.0"
       
     5 // which accompanies this distribution, and is available
       
     6 // at the URL "http://www.eclipse.org/legal/epl-v10.html".
       
     7 //
       
     8 // Initial Contributors:
       
     9 // Nokia Corporation - initial contribution.
       
    10 //
       
    11 // Contributors:
       
    12 //
       
    13 // Description:
       
    14 // f32\sfile\sf_cache_man.cpp
       
    15 // 
       
    16 //
       
    17 
       
    18 /**
       
    19  @file
       
    20  @internalTechnology
       
    21 */
       
    22 
       
    23 
       
    24 #include <e32std.h>
       
    25 #include <e32std_private.h>
       
    26 #include "sf_std.h"
       
    27 #include <e32uid.h>
       
    28 #include <e32wins.h>
       
    29 #include <f32file.h>
       
    30 #include <hal.h>
       
    31 #include "sf_cache_man.h"
       
    32 #include "sf_cache_client.h"
       
    33 #include "sf_file_cache.h"
       
    34 #include "sf_file_cache_defs.h"
       
    35 
       
    36 //#undef __SIMULATE_LOCK_FAILURES__
       
    37 //#define __RAMDOM_LOCK_FAILURES__
       
    38 //#define __PSEUDO_RANDOM_FAILURES__		
       
    39 //#define __LOCK_ENTIRE_CACHELINE__
       
    40 
       
    41 #ifdef __RAMDOM_LOCK_FAILURES__	
       
    42 #include <e32math.h>
       
    43 #endif
       
    44 
       
    45 #define CACHE_NUM_TO_ADDR(n) (iBase + (n << iCacheLineSizeLog2))
       
    46 #define ADDR_TO_CACHELINE_ADDR(a) ((((a - iBase) >> iCacheLineSizeLog2) << iCacheLineSizeLog2) + iBase)
       
    47 #define ADDR_TO_INDEX(a) ((a - iBase) >> iCacheLineSizeLog2)
       
    48 
       
    49 #if defined(_DEBUG)
       
    50 	#define __CACHELINE_INVARIANT(aCacheLine)						\
       
    51 	__ASSERT_DEBUG(												\
       
    52 		aCacheLine.iDirtySegments <= aCacheLine.iFilledSegments &&	\
       
    53 		aCacheLine.iFilledSegments <= aCacheLine.iAllocatedSegments,	\
       
    54 		Fault(EInvalidCacheLine));
       
    55 
       
    56 #else
       
    57 	#define __CACHELINE_INVARIANT(aCacheLine)
       
    58 #endif
       
    59 
       
    60 const TInt KSegmentSize = 4096;
       
    61 const TInt KSegmentSizeLog2 = 12;
       
    62 const TInt64 KSegmentSizeMask = MAKE_TINT64(0x7FFFFFFF,0xFFFFF000);
       
    63 
       
    64 const TInt KCacheLineSizeLog2 = 17;	// 128K
       
    65 const TInt KCacheLineSize = (1 << KCacheLineSizeLog2 );
       
    66 const TInt KCacheLineSizeInSegments = (KCacheLineSize >> KSegmentSizeLog2);
       
    67 
       
    68 CCacheManager* CCacheManagerFactory::iCacheManager = NULL;
       
    69 
       
    70 
       
    71 LOCAL_C void Fault(TCacheManagerFault aFault)
       
    72 //
       
    73 // Report a fault in the cache manager
       
    74 //
       
    75 	{
       
    76 	User::Panic(_L("FSCACHEMAN"), aFault);
       
    77 	}
       
    78 
       
    79 
       
    80 /*
       
    81 Indicates if a number passed in is a power of two
       
    82 
       
    83 @param aNum number to be tested
       
    84 @return Flag to indicate the result of the test
       
    85 */
       
    86 LOCAL_C TBool IsPowerOfTwo(TInt aNum)
       
    87 	{
       
    88 	return (aNum != 0 && (aNum & -aNum) == aNum);
       
    89 	}
       
    90 
       
    91 
       
    92 //********************
       
    93 // CCacheManagerFactory
       
    94 //********************
       
    95 void CCacheManagerFactory::CreateL()
       
    96 	{
       
    97 	__ASSERT_ALWAYS(iCacheManager == NULL, Fault(ECacheAlreadyCreated));
       
    98 
       
    99 	if (TGlobalFileCacheSettings::Enabled())
       
   100 		{
       
   101 		iCacheManager = CCacheManager::NewCacheL(TGlobalFileCacheSettings::CacheSize());
       
   102 		}
       
   103 	else
       
   104 		{
       
   105 		Destroy(); 
       
   106 		}
       
   107 	}
       
   108 
       
   109 CCacheManager* CCacheManagerFactory::CacheManager()
       
   110 	{
       
   111 	return iCacheManager;
       
   112 	}
       
   113 
       
   114 TInt CCacheManagerFactory::Destroy()
       
   115 	{
       
   116 	delete iCacheManager;
       
   117 	iCacheManager = NULL;
       
   118 	return KErrNone;
       
   119 	}
       
   120 
       
   121 //********************
       
   122 // CCacheManager
       
   123 //********************
       
   124 CCacheManager* CCacheManager::NewCacheL(TInt aCacheSize)
       
   125 	{
       
   126 	CCacheManager* cacheManager = new (ELeave) CCacheManager(aCacheSize);
       
   127 
       
   128 	CleanupStack::PushL(cacheManager);
       
   129 	cacheManager->ConstructL();
       
   130 	CleanupStack::Pop(1, cacheManager);
       
   131 
       
   132 	return cacheManager;
       
   133 	}
       
   134 
       
   135 CCacheManager::~CCacheManager()
       
   136 	{
       
   137 	CacheLock();
       
   138 
       
   139 	iFreeQueue.Close();
       
   140 	iUsedQueue.Close();
       
   141 
       
   142 	delete [] iCacheLines;
       
   143 
       
   144 	CacheUnlock();
       
   145 	iLock.Close();
       
   146 
       
   147 	iChunk.Close();
       
   148 	}
       
   149 
       
   150 
       
   151 CCacheManager::CCacheManager(TUint aCacheSize)
       
   152 	{
       
   153 	// Get the page size
       
   154 	TInt pageSize;
       
   155 	TInt r = HAL::Get(HAL::EMemoryPageSize, pageSize);
       
   156 	if (r != KErrNone)
       
   157 		pageSize = KSegmentSize;
       
   158 	__ASSERT_ALWAYS(IsPowerOfTwo(pageSize), Fault(EIllegalPageSize));
       
   159 
       
   160 	// For the time being we only a support page size of 4K and we assume
       
   161 	// that page size = segment size, since the extra overhead of supporting 
       
   162 	// variable page sizes now is non-trivial.
       
   163 	//
       
   164 	// If a processor with a different page size needs to be supported 
       
   165 	// in the future, then we need to either rework this code to be able to
       
   166 	// devide up pages into smaller segments or analyze the impact of having 
       
   167 	// a different page size on performance.
       
   168 	__ASSERT_ALWAYS(pageSize == KSegmentSize, Fault(EIllegalPageSize));
       
   169 
       
   170 	iCacheLineSize = KCacheLineSize;
       
   171 	iCacheLineSizeLog2 = KCacheLineSizeLog2;
       
   172 
       
   173 	iCacheSize = aCacheSize;
       
   174 
       
   175 	iSegmentsPerCacheLine = 1 << (iCacheLineSizeLog2 - KSegmentSizeLog2);
       
   176 
       
   177 	iMaxLockedSegments = TGlobalFileCacheSettings::MaxLockedSize() >> KSegmentSizeLog2;
       
   178 
       
   179 #ifdef __SIMULATE_LOCK_FAILURES__
       
   180 	iSimulateLockFailureMode = ETrue;
       
   181 #endif
       
   182 	}
       
   183 
       
   184 void CCacheManager::ConstructL()
       
   185 	{
       
   186 
       
   187 	// calculate the low-memory threshold below which we fail any attempt to allocate memory
       
   188 	TMemoryInfoV1Buf meminfo;
       
   189 	TInt r = UserHal::MemoryInfo(meminfo);
       
   190 	__ASSERT_ALWAYS(r==KErrNone,Fault(EMemoryInfoFailed));
       
   191 
       
   192 	iLowMemoryThreshold = (meminfo().iTotalRamInBytes * TGlobalFileCacheSettings::LowMemoryThreshold()) / 100;
       
   193 	__CACHE_PRINT4(_L("CACHEMAN: totalRAM %d freeRAM %d KDefaultLowMemoryThresholdPercent %d iLowMemoryThreshold %d"), 
       
   194 		meminfo().iTotalRamInBytes, meminfo().iFreeRamInBytes, KDefaultLowMemoryThreshold, iLowMemoryThreshold);
       
   195 	__CACHE_PRINT1(_L("CACHEMAN: iCacheSize %d"), iCacheSize);
       
   196 	TChunkCreateInfo createInfo;
       
   197 	createInfo.SetCache(iCacheSize);
       
   198 	createInfo.SetOwner(EOwnerProcess);
       
   199 	r = iChunk.Create(createInfo);
       
   200 	User::LeaveIfError(r);
       
   201 
       
   202 	
       
   203 	TInt mm = UserSvr::HalFunction(EHalGroupKernel, EKernelHalMemModelInfo, 0, 0) & EMemModelTypeMask;
       
   204 	if (mm < EMemModelTypeFlexible)
       
   205 		{
       
   206 		// On memory models before flexible, File System has to register chunks that will be DMA-ed.
       
   207 		// On flexible memory model, local media is using new physical pinning Kernel interface that
       
   208 		// doesn't require registration of the chunk.
       
   209 		UserSvr::RegisterTrustedChunk(iChunk.Handle());
       
   210 		}
       
   211 	
       
   212 
       
   213 	__ASSERT_ALWAYS(iCacheSize > KSegmentSize, Fault(EIllegalCacheSize));
       
   214 
       
   215 	r = iLock.CreateLocal();
       
   216 	User::LeaveIfError(r);
       
   217 
       
   218 	iNumOfCacheLines = iCacheSize >> iCacheLineSizeLog2;
       
   219 	iBase = Base();
       
   220 
       
   221 	iCacheLines = new (ELeave) TCacheLine[iNumOfCacheLines];
       
   222 
       
   223 	for (TInt n=0; n<iNumOfCacheLines; n++)
       
   224 		{
       
   225 		// coverity[var_decl]
       
   226 		TCacheLine cacheLine;
       
   227 		cacheLine.iAddr = CACHE_NUM_TO_ADDR(n);
       
   228 		cacheLine.iAllocatedSegments = 0;
       
   229 		cacheLine.iFilledSegments = 0;
       
   230 		cacheLine.iDirtySegments = 0;
       
   231 		cacheLine.iLockCount = 0;
       
   232 		cacheLine.iLockedSegmentStart = 0;
       
   233 		cacheLine.iLockedSegmentCount = 0;
       
   234 		cacheLine.iClient = NULL;
       
   235 		// coverity[uninit_use]
       
   236 		iCacheLines[n] = cacheLine;
       
   237 
       
   238 		r = iFreeQueue.Append(&iCacheLines[n]);
       
   239 		User::LeaveIfError(r);
       
   240 		}
       
   241 
       
   242 	}
       
   243 
       
   244 CCacheClient* CCacheManager::CreateClientL()
       
   245 	{
       
   246 	CCacheClient* client = CCacheClient::NewL(*this);
       
   247 	return client;
       
   248 	}
       
   249 
       
   250 void CCacheManager::RegisterClient(CCacheClient& /*aClient*/)
       
   251 	{
       
   252 #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
       
   253 	iStats.iFileCount++;
       
   254 #endif
       
   255 	}
       
   256 
       
   257 void CCacheManager::DeregisterClient(CCacheClient& /*aClient*/)
       
   258 	{
       
   259 #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
       
   260 	iStats.iFileCount--;
       
   261 #endif
       
   262 	}
       
   263 
       
   264 
       
   265 void CCacheManager::FreeMemoryChanged(TBool aMemoryLow)
       
   266 	{
       
   267 	iMemoryLow = aMemoryLow;
       
   268 	}
       
   269 
       
   270 TBool CCacheManager::TooManyLockedSegments()
       
   271 	{
       
   272 	return (iLockedSegmentCount >= iMaxLockedSegments)?(TBool)ETrue:(TBool)EFalse;
       
   273 	}
       
   274 
       
   275 TInt CCacheManager::SegmentSize()
       
   276 	{
       
   277 	return KSegmentSize;
       
   278 	}
       
   279 
       
   280 TInt CCacheManager::SegmentSizeLog2()
       
   281 	{
       
   282 	return KSegmentSizeLog2;
       
   283 	}
       
   284 
       
   285 TInt64 CCacheManager::SegmentSizeMask()
       
   286 	{
       
   287 	return KSegmentSizeMask;
       
   288 	}
       
   289 
       
   290 TInt CCacheManager::CacheLineSize()
       
   291 	{
       
   292 	return KCacheLineSize;
       
   293 	}
       
   294 
       
   295 TInt CCacheManager::CacheLineSizeInSegments()
       
   296 	{
       
   297 	return KCacheLineSizeInSegments;
       
   298 	}
       
   299 
       
   300 TInt CCacheManager::CacheLineSizeLog2()
       
   301 	{
       
   302 	return KCacheLineSizeLog2;
       
   303 	}
       
   304 
       
   305 
       
   306 #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
       
   307 TFileCacheStats& CCacheManager::Stats()
       
   308 	{
       
   309 	iStats.iFreeCount = iFreeQueue.Count();
       
   310 	iStats.iUsedCount = iUsedQueue.Count();
       
   311 	iStats.iLockedSegmentCount = iLockedSegmentCount;
       
   312 	iStats.iFilesOnClosedQueue = TClosedFileUtils::Count();
       
   313 	__ASSERT_DEBUG(iStats.iFreeCount >= 0, Fault(EInvalidStats));
       
   314 	__ASSERT_DEBUG(iStats.iUsedCount >= 0, Fault(EInvalidStats));
       
   315 	__ASSERT_DEBUG(iStats.iLockedSegmentCount >= 0, Fault(EInvalidStats));
       
   316 	__ASSERT_DEBUG(iStats.iFilesOnClosedQueue >= 0, Fault(EInvalidStats));
       
   317 	return iStats;
       
   318 	}
       
   319 #endif	// #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
       
   320 
       
   321 
       
   322 
       
   323 void CCacheManager::CacheLock()
       
   324 	{
       
   325 	iLock.Wait();
       
   326 
       
   327 #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
       
   328 	iManagerLocked = ETrue;
       
   329 #endif
       
   330 	}
       
   331 
       
   332 void CCacheManager::CacheUnlock()
       
   333 	{
       
   334 #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
       
   335 	iManagerLocked = EFalse;
       
   336 #endif
       
   337 	iLock.Signal();
       
   338 	}
       
   339 
       
   340 
       
   341 TInt CCacheManager::AllocateAndLockCacheLine(CCacheClient* aClient, TInt64 aPos, const TCacheLine*& aCacheLine, TInt aSegmentCount)
       
   342 	{
       
   343 	__ASSERT_DEBUG(aSegmentCount <= iSegmentsPerCacheLine, Fault(EInvalidAllocCount));
       
   344 
       
   345 	// check for low system memory
       
   346 	TMemoryInfoV1Buf meminfo;
       
   347 	TInt r = UserHal::MemoryInfo(meminfo);
       
   348 	__ASSERT_ALWAYS(r==KErrNone,Fault(EMemoryInfoFailed));
       
   349 	if (iMemoryLow || (meminfo().iFreeRamInBytes < iLowMemoryThreshold))
       
   350 		{
       
   351 		__CACHE_PRINT(_L("CACHEMAN: free RAM below threshold !!!"));
       
   352 		return KErrNoMemory;
       
   353 		}
       
   354 
       
   355 	CacheLock();
       
   356 
       
   357 	__CACHE_PRINT1(_L("CACHEMAN: Allocate %d segments, Lock %d"), aSegmentCount);
       
   358 	__CACHE_PRINT2(_L("CACHEMAN: iFreeQueue %d iUsedQueue %d"), iFreeQueue.Count(), iUsedQueue.Count());
       
   359 
       
   360 #ifdef  __SIMULATE_LOCK_FAILURES__
       
   361 	if (SimulatedFailure(iAllocFailureCount))
       
   362 		{
       
   363 		__CACHE_PRINT(_L("CACHEMAN: simulating allocation failure"));
       
   364 		CacheUnlock();
       
   365 		return KErrNoMemory;
       
   366 		}
       
   367 #endif
       
   368 
       
   369 	// any cachelines free ?
       
   370 	TInt freeCacheLines = iFreeQueue.Count();
       
   371 	TCacheLine* cacheLine = NULL;
       
   372 	if (freeCacheLines == 0 && !StealCacheLine(aClient))
       
   373 		{
       
   374 		CacheUnlock();
       
   375 		return KErrNotFound;
       
   376 		}
       
   377 
       
   378 	cacheLine = iFreeQueue[0];
       
   379 
       
   380 	__CACHELINE_INVARIANT((*cacheLine));
       
   381 	__ASSERT_DEBUG( cacheLine->iAllocatedSegments == 0, Fault(EInvalidAllocCount));
       
   382 	__ASSERT_DEBUG( cacheLine->iFilledSegments == 0, Fault(EInvalidFillCount));
       
   383 	__ASSERT_DEBUG( cacheLine->iDirtySegments == 0, Fault(EInvalidFillCount));
       
   384 	__ASSERT_DEBUG( cacheLine->iLockCount == 0, Fault(EInvalidLockCount));
       
   385 	__ASSERT_DEBUG( cacheLine->iLockedSegmentStart == 0, Fault(EInvalidLockedPageStart));
       
   386 	__ASSERT_DEBUG( cacheLine->iLockedSegmentCount == 0, Fault(EInvalidLockedPageCount));
       
   387 	__ASSERT_DEBUG( cacheLine->iClient == NULL, Fault(EInvalidClient));
       
   388 
       
   389 	TUint8* addr = cacheLine->iAddr;
       
   390 
       
   391 	// Commit it
       
   392 	r = Commit(addr, aSegmentCount);
       
   393 	if (r != KErrNone)
       
   394 		{
       
   395 		CacheUnlock();
       
   396 		return r;
       
   397 		}
       
   398 	cacheLine->iAllocatedSegments = (TUint8) (aSegmentCount);
       
   399 	cacheLine->iLockedSegmentStart = 0;
       
   400 	cacheLine->iLockedSegmentCount = (TUint8) aSegmentCount;
       
   401 
       
   402 	// Add to used queue
       
   403 	r = iUsedQueue.InsertInAddressOrder(cacheLine);
       
   404 	if (r != KErrNone)
       
   405 		{
       
   406 		Decommit(addr, aSegmentCount);
       
   407 		CacheUnlock();
       
   408 		return r;
       
   409 		}
       
   410 
       
   411 	cacheLine->iClient = aClient;
       
   412 	cacheLine->iPos = aPos;
       
   413 
       
   414 	// Remove from free queue
       
   415 	iFreeQueue.Remove(0);
       
   416 
       
   417 	// RChunk will lock segments initially unless explicitly unlocked
       
   418 
       
   419 	cacheLine->iLockCount++;
       
   420 	
       
   421 	__CACHE_PRINT2(_L("CACHEMAN: LockCount for %08X is %d"), cacheLine->iAddr, cacheLine->iLockCount);
       
   422 
       
   423 	CacheUnlock();
       
   424 
       
   425 	aCacheLine = cacheLine;
       
   426 	return r;
       
   427 
       
   428 	}
       
   429 
       
   430 /**
       
   431 CCacheManager::ExtendCacheLine()
       
   432 
       
   433 Attempts to extend the length of an existing cacheline by committing extra segments
       
   434 The cacheline must be owned and locked already.
       
   435 
       
   436 @param aCacheLine A reference to a locked, owned cacheline
       
   437 @param aSegmentCount The new length of the cacheline (including the existing segments)
       
   438 					 This must be greater then the existing length.
       
   439 
       
   440 @return KErrNone if successful
       
   441 		or other system wide error code.
       
   442 */
       
   443 TInt CCacheManager::ExtendCacheLine(CCacheClient* aClient, const TCacheLine& aCacheLine, TInt aSegmentCount)
       
   444 	{
       
   445 	CacheLock();
       
   446 
       
   447 	__ASSERT_DEBUG(aSegmentCount > 0, Fault(EInvalidSegmentCount));
       
   448 
       
   449 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
       
   450 	__CACHELINE_INVARIANT((cacheLine));
       
   451 	__ASSERT_DEBUG(aSegmentCount <= iSegmentsPerCacheLine, Fault(EInvalidSegmentCount));
       
   452 	__ASSERT_DEBUG(aSegmentCount > cacheLine.iAllocatedSegments, Fault(EInvalidSegmentCount));
       
   453 	__ASSERT_DEBUG(cacheLine.iLockCount > 0, Fault(EInvalidLockCount));	// must be locked already
       
   454 	__ASSERT_ALWAYS(cacheLine.iClient == aClient, Fault(EExtendingUnownedCacheline));
       
   455 
       
   456 	// ensure all pages in cachline are locked
       
   457 	__ASSERT_DEBUG(cacheLine.iLockedSegmentStart == 0, Fault(EInvalidLockRange));
       
   458 	__ASSERT_DEBUG(cacheLine.iLockedSegmentCount == cacheLine.iAllocatedSegments, Fault(EInvalidLockRange));
       
   459 
       
   460 	__CACHE_PRINT2(_L("CACHEMAN: ExtendCacheLine(%08X, %d)"), cacheLine.iAddr, aSegmentCount);
       
   461 
       
   462 	// Commit the new segments
       
   463 	TUint8* addrNewSegment = cacheLine.iAddr + (cacheLine.iAllocatedSegments << KSegmentSizeLog2);
       
   464 	TInt segmentCountNew = aSegmentCount - cacheLine.iAllocatedSegments;
       
   465 
       
   466 	TInt r = Commit(addrNewSegment, segmentCountNew);
       
   467 	if (r == KErrNone)
       
   468 		{
       
   469 		cacheLine.iAllocatedSegments = cacheLine.iLockedSegmentCount = (TUint8) aSegmentCount;
       
   470 		}
       
   471 	
       
   472 
       
   473 	CacheUnlock();
       
   474 	return r;
       
   475 	}
       
   476 
       
   477 /**
       
   478 CCacheManager::ReUseCacheLine()
       
   479 
       
   480 Attempts to lock and then extend or shrink an already owned cacheline, ready for re-use.
       
   481 If successful the cacheline is returned locked and all segments are marked as empty.
       
   482 The cacheline must initially be unlocked.
       
   483 
       
   484 @param aCacheLine A reference to an unlocked cacheline
       
   485 @param aSegmentCount The new length of the cacheline;
       
   486 					 this may be greater or less than the existing length.
       
   487 
       
   488 @return KErrNone if successful
       
   489 		or other system wide error code.
       
   490 */
       
   491 TInt CCacheManager::ReAllocateAndLockCacheLine(CCacheClient* aClient, TInt64 aPos, const TCacheLine& aCacheLine, TInt aSegmentCount)
       
   492 	{
       
   493 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
       
   494 	__CACHELINE_INVARIANT((cacheLine));
       
   495 
       
   496 	__ASSERT_DEBUG(aSegmentCount > 0, Fault(EInvalidSegmentCount));
       
   497 	__ASSERT_DEBUG(aSegmentCount <= iSegmentsPerCacheLine, Fault(EInvalidSegmentCount));
       
   498 
       
   499 	__CACHE_PRINT2(_L("CACHEMAN: ReUseCacheLine(%08X, %d)"), cacheLine.iAddr, aSegmentCount);
       
   500 
       
   501 	TInt r;
       
   502 	// old cacheline same size or bigger ?
       
   503 	if (cacheLine.iAllocatedSegments >= aSegmentCount)
       
   504 		{
       
   505 		r = LockCacheLine(aClient, aCacheLine, 0, aSegmentCount);
       
   506 		if (r!= KErrNone)
       
   507 			return r;
       
   508 		if (cacheLine.iAllocatedSegments > aSegmentCount)
       
   509 			{
       
   510 			cacheLine.iFilledSegments = (TUint8) aSegmentCount;
       
   511 			RemoveEmptySegments(aClient, aCacheLine);
       
   512 			}
       
   513 		}
       
   514 	// old cacheline smaller
       
   515 	else 
       
   516 		{
       
   517 		r = LockCacheLine(aClient, aCacheLine, 0, cacheLine.iAllocatedSegments);
       
   518 		if (r != KErrNone)
       
   519 			return r;
       
   520 		r = ExtendCacheLine(aClient, aCacheLine, aSegmentCount);
       
   521 		if (r != KErrNone)
       
   522 			{
       
   523 			UnlockCacheLine(aClient, aCacheLine);
       
   524 			return r;
       
   525 			}
       
   526 		}
       
   527 	cacheLine.iFilledSegments = 0;
       
   528 	cacheLine.iPos = aPos;
       
   529 
       
   530 	return KErrNone;
       
   531 	}
       
   532 
       
   533 
       
   534 /**
       
   535 CCacheManager::LockCacheLine()
       
   536 
       
   537 @return KErrNone on success
       
   538 */
       
   539 TInt CCacheManager::LockCacheLine(
       
   540 	CCacheClient* aClient, 
       
   541 	const TCacheLine& aCacheLine,
       
   542 	TInt aLockedPageStart,
       
   543 	TInt aLockedPageCount)
       
   544 	{
       
   545 	CacheLock();
       
   546 
       
   547 
       
   548 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
       
   549 	__CACHELINE_INVARIANT((cacheLine));
       
   550 	
       
   551 	// has the cacheline been stolen ?
       
   552 	if (cacheLine.iClient != aClient)
       
   553 		{
       
   554 		__CACHE_PRINT(_L("CCacheManager::LockCacheLine(), Cacheline Stolen !\n"));
       
   555 		CacheUnlock();
       
   556 		return KErrNotFound;
       
   557 		}
       
   558 	
       
   559 	// validate lock range
       
   560 	__ASSERT_DEBUG(aLockedPageStart >= 0, Fault(EInvalidLockRange));
       
   561 	__ASSERT_DEBUG(aLockedPageStart + aLockedPageCount <= cacheLine.iAllocatedSegments, Fault(EInvalidLockRange));
       
   562 	__ASSERT_DEBUG(aLockedPageCount <= iSegmentsPerCacheLine, Fault(EInvalidLockRange));
       
   563 	// if already locked, don't allow lock range to grow down or up (to simplify code)
       
   564 	__ASSERT_DEBUG(cacheLine.iLockCount == 0 || 
       
   565 			aLockedPageStart >= cacheLine.iLockedSegmentStart, 
       
   566 		Fault(EInvalidLockRange));
       
   567 	__ASSERT_DEBUG(cacheLine.iLockCount == 0 || 
       
   568 		aLockedPageStart + aLockedPageCount <= cacheLine.iLockedSegmentStart + cacheLine.iLockedSegmentCount, 
       
   569 		Fault(EInvalidLockRange));
       
   570 	
       
   571 	__CACHE_PRINT1(_L("CACHEMAN: LockCacheLine(%08X, %d)"), cacheLine.iAddr);
       
   572 
       
   573 	if (InUse(aCacheLine))
       
   574 		{
       
   575 		__CACHE_PRINT(_L("CCacheManager::LockCacheLine(), Cacheline in use !\n"));
       
   576 		CacheUnlock();
       
   577 		return KErrInUse;
       
   578 		}
       
   579 
       
   580 	TInt lockErr = KErrNone;
       
   581 	
       
   582 	// increment the lock count
       
   583 	// if not already locked, lock requested segments
       
   584 	if (cacheLine.iLockCount++ == 0)
       
   585 		{
       
   586 #ifdef __LOCK_ENTIRE_CACHELINE__
       
   587 		lockErr = Lock(cacheLine.iAddr, cacheLine.iAllocatedSegments);
       
   588 #else
       
   589 		__ASSERT_DEBUG(cacheLine.iDirtySegments == 0, Fault(ELockingAndAlreadyDirty));
       
   590 		lockErr = Lock(	cacheLine.iAddr + (aLockedPageStart<<KSegmentSizeLog2), aLockedPageCount);
       
   591 #endif
       
   592 
       
   593 		if (lockErr == KErrNone)
       
   594 			{
       
   595 			cacheLine.iLockedSegmentStart = (TUint8) aLockedPageStart;
       
   596 			cacheLine.iLockedSegmentCount = (TUint8) aLockedPageCount;
       
   597 			}
       
   598 		else	// if (lockErr != KErrNone)
       
   599 			{
       
   600 			__CACHE_PRINT2(_L("CACHEMAN: LockCacheLine(%08X) failure %d"), cacheLine.iAddr, lockErr);
       
   601 			cacheLine.iLockCount--;
       
   602 			// NB a lock failure implies segment is decomitted
       
   603 			FreeCacheLine(cacheLine);
       
   604 			}
       
   605 		}
       
   606 	// if already locked (because cacheline is dirty) ensure lock range 
       
   607 	// isn't growing (this isn't allowed to keep the code simpler) 
       
   608 	else
       
   609 		{
       
   610 		__ASSERT_DEBUG(cacheLine.iLockedSegmentStart == 0, Fault(EInvalidLockRange));
       
   611 		__ASSERT_DEBUG(cacheLine.iLockedSegmentCount >= aLockedPageStart + aLockedPageCount, Fault(EInvalidLockRange));
       
   612 		}
       
   613 
       
   614 	CacheUnlock();
       
   615 	return lockErr;
       
   616 	}
       
   617 
       
   618 /**
       
   619 UnlockCacheLine()
       
   620 */
       
   621 TBool CCacheManager::UnlockCacheLine(CCacheClient* aClient, const TCacheLine& aCacheLine)
       
   622 	{
       
   623 	CacheLock();
       
   624 
       
   625 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
       
   626 	__CACHELINE_INVARIANT((cacheLine));
       
   627 	
       
   628 	__ASSERT_DEBUG(cacheLine.iLockCount > 0, Fault(EInvalidLockCount));
       
   629 	__ASSERT_ALWAYS(cacheLine.iClient == aClient, Fault(EUnlockingUnownedCacheline));
       
   630 
       
   631 	
       
   632 	__CACHE_PRINT2(_L("CACHEMAN: UnlockCacheLine(%08X, %d)"), cacheLine.iAddr, cacheLine.iAllocatedSegments);
       
   633 
       
   634 
       
   635 	// decrement the lock count
       
   636 	TBool success = ETrue;
       
   637 
       
   638 	if (cacheLine.iLockCount > 1)
       
   639 		{
       
   640 		cacheLine.iLockCount--;
       
   641 		}
       
   642 	else
       
   643 		{
       
   644 		if (cacheLine.iDirtySegments == 0)
       
   645 			{
       
   646 			cacheLine.iLockCount--;
       
   647 #ifdef __LOCK_ENTIRE_CACHELINE__
       
   648 			Unlock(cacheLine.iAddr, cacheLine.iAllocatedSegments);
       
   649 #else
       
   650 			Unlock(
       
   651 				cacheLine.iAddr + (cacheLine.iLockedSegmentStart<<KSegmentSizeLog2), 
       
   652 				cacheLine.iLockedSegmentCount);
       
   653 #endif
       
   654 
       
   655 			cacheLine.iLockedSegmentStart = cacheLine.iLockedSegmentCount = 0;
       
   656 			}
       
   657 		else
       
   658 			{
       
   659 			__CACHE_PRINT(_L("CACHEMAN: UnlockCacheLine - not unlocking segment dirty"));
       
   660 			success = EFalse;
       
   661 			}
       
   662 		}
       
   663 
       
   664 	CacheUnlock();
       
   665 
       
   666 	return success;
       
   667 	}
       
   668 
       
   669 
       
   670 
       
   671 TBool CCacheManager::StealCacheLine(CCacheClient* aClient)
       
   672 	{
       
   673 	__ASSERT_DEBUG(iManagerLocked, Fault(EManagerNotLocked));
       
   674 
       
   675 	TInt usedQueueSize = iUsedQueue.Count();
       
   676 
       
   677 	#define INC_INDEX(x) (x++, x = (x >= usedQueueSize ? 0 : x))
       
   678 
       
   679 	__CACHE_PRINT2(_L("CACHEMAN: StealCacheLine, iNextCacheLineToSteal %d used count %d"), iNextCacheLineToSteal, iUsedQueue.Count());
       
   680 
       
   681 	TInt iInitIndex = iNextCacheLineToSteal;
       
   682 
       
   683 	// Loop through all used cachelines, starting at the last stolen 
       
   684 	// cacheline index + 1 and ending when we find a suitable cacheline 
       
   685 	// to steal or we have looped back to the start
       
   686 	for (INC_INDEX(iNextCacheLineToSteal);
       
   687 		iNextCacheLineToSteal != iInitIndex; 
       
   688 		INC_INDEX(iNextCacheLineToSteal))
       
   689 		{
       
   690 		TCacheLine& cacheLine = *iUsedQueue[iNextCacheLineToSteal];
       
   691 		if (cacheLine.iLockCount == 0 && cacheLine.iClient != aClient)
       
   692 			{
       
   693 			__CACHE_PRINT3(_L("CACHEMAN: StealCacheLine, stealing %d from %08X to %08X"), 
       
   694 				  iNextCacheLineToSteal, cacheLine.iClient, aClient);
       
   695 			FreeCacheLine(cacheLine);
       
   696 			return ETrue;
       
   697 			}
       
   698 		}
       
   699 	return EFalse;
       
   700 	}
       
   701 
       
   702 
       
   703 TBool CCacheManager::FreeCacheLine(CCacheClient* aClient, const TCacheLine& aCacheLine)
       
   704 	{
       
   705 	CacheLock();
       
   706 
       
   707 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
       
   708 	__CACHELINE_INVARIANT((cacheLine));
       
   709 
       
   710 	// Has the cacheline been stolen ? (Assume success if it has)
       
   711 	if (cacheLine.iClient != aClient)
       
   712 		{
       
   713 		__CACHE_PRINT(_L("CCacheManager::FreeCacheLine(), Cacheline Stolen !!!!\n"));
       
   714 		CacheUnlock();
       
   715 		return ETrue;		
       
   716 		}
       
   717 	
       
   718 	// Is the cacheline locked ?
       
   719 	if (cacheLine.iLockCount > 0)
       
   720 		{
       
   721 		__CACHE_PRINT(_L("CCacheManager::FreeCacheLine(), attempt to free locked cacheline\n"));
       
   722 		CacheUnlock();
       
   723 		return EFalse;
       
   724 		}
       
   725 
       
   726 	FreeCacheLine(cacheLine);
       
   727 
       
   728 	CacheUnlock();
       
   729 	return ETrue;
       
   730 	}
       
   731 
       
   732 TInt CCacheManager::LockCount(CCacheClient* aClient, const TCacheLine& aCacheLine)
       
   733 	{
       
   734 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
       
   735 	__CACHELINE_INVARIANT((cacheLine));
       
   736 	
       
   737 	// cacheline stolen ?
       
   738 	if (cacheLine.iClient != aClient)
       
   739 		return 0;
       
   740 
       
   741 	return cacheLine.iLockCount;
       
   742 	}
       
   743 
       
   744 TInt CCacheManager::FillCount(CCacheClient* aClient, const TCacheLine& aCacheLine)
       
   745 	{
       
   746 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
       
   747 	__CACHELINE_INVARIANT((cacheLine));
       
   748 	
       
   749 	// cacheline stolen ?
       
   750 	if (cacheLine.iClient != aClient)
       
   751 		return 0;
       
   752 
       
   753 	return cacheLine.iFilledSegments;
       
   754 	}
       
   755 
       
   756 TInt CCacheManager::DirtyCount(CCacheClient* aClient, const TCacheLine& aCacheLine)
       
   757 	{
       
   758 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
       
   759 	__CACHELINE_INVARIANT((cacheLine));
       
   760 
       
   761 	// cacheline stolen ?
       
   762 	if (cacheLine.iClient != aClient)
       
   763 		return 0;
       
   764 
       
   765 	return cacheLine.iDirtySegments;
       
   766 	}
       
   767 
       
   768 TBool CCacheManager::InUse(const TCacheLine& aCacheLine)
       
   769 	{
       
   770 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
       
   771 	__CACHELINE_INVARIANT((cacheLine));
       
   772 
       
   773 	// busy if lock count >= 1 and there are no dirty segments
       
   774 	// or   if lock count >= 2 and there are dirty segments
       
   775 	return (cacheLine.iLockCount - 
       
   776 		   (cacheLine.iDirtySegments?1:0)) > 0 ? (TBool)ETrue : (TBool)EFalse;
       
   777 	}
       
   778 
       
   779 void CCacheManager::SetFilled(CCacheClient* aClient, const TCacheLine& aCacheLine,  TInt aSegmentCount)
       
   780 	{
       
   781 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
       
   782 	__CACHELINE_INVARIANT((cacheLine));
       
   783 	__ASSERT_DEBUG(aSegmentCount <= iSegmentsPerCacheLine, Fault(EInvalidSegmentCount));
       
   784 	__ASSERT_DEBUG(aSegmentCount <= cacheLine.iAllocatedSegments , Fault(EInvalidDirtyCount));
       
   785 	__ASSERT_DEBUG(cacheLine.iLockCount > 0, Fault(ESetFilledNotLocked));
       
   786 	__ASSERT_ALWAYS(cacheLine.iClient == aClient, Fault(EExtendingUnownedCacheline));
       
   787 
       
   788 	
       
   789 	cacheLine.iFilledSegments = Max(cacheLine.iFilledSegments, (TUint8) aSegmentCount);
       
   790 
       
   791 	__ASSERT_DEBUG(cacheLine.iFilledSegments >= cacheLine.iDirtySegments , Fault(EInvalidDirtyCount));
       
   792 	}
       
   793 
       
   794 void CCacheManager::SetDirty(CCacheClient* aClient, const TCacheLine& aCacheLine,  TInt aSegmentCount)
       
   795 	{
       
   796 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
       
   797 	__CACHELINE_INVARIANT((cacheLine));
       
   798 	__ASSERT_DEBUG(aSegmentCount <= iSegmentsPerCacheLine, Fault(EInvalidSegmentCount));
       
   799 	__ASSERT_DEBUG(aSegmentCount <= cacheLine.iAllocatedSegments , Fault(EInvalidDirtyCount));
       
   800 	__ASSERT_DEBUG(cacheLine.iLockCount > 0, Fault(ESetDirtyNotLocked));
       
   801 	__ASSERT_ALWAYS(cacheLine.iClient == aClient, Fault(EExtendingUnownedCacheline));
       
   802 
       
   803 	// ensure that lock range is valid - we insist on dirty
       
   804 	// cachelines having all dirty pages locked up to the the last dirty page
       
   805 	__ASSERT_DEBUG(cacheLine.iLockedSegmentStart == 0, Fault(ESetDirtyInvalidLockRange));
       
   806 	__ASSERT_DEBUG(cacheLine.iLockedSegmentCount >= aSegmentCount, Fault(ESetDirtyInvalidLockRange));
       
   807 	
       
   808 	cacheLine.iFilledSegments = Max(cacheLine.iFilledSegments, (TUint8) aSegmentCount);
       
   809 	cacheLine.iDirtySegments = Max(cacheLine.iDirtySegments, (TUint8) aSegmentCount);
       
   810 
       
   811 	__ASSERT_DEBUG(cacheLine.iFilledSegments >= cacheLine.iDirtySegments , Fault(EInvalidDirtyCount));
       
   812 	}
       
   813 
       
   814 void CCacheManager::ClearDirty(CCacheClient* aClient, const TCacheLine& aCacheLine)
       
   815 	{
       
   816 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
       
   817 	__CACHELINE_INVARIANT((cacheLine));
       
   818 	__ASSERT_DEBUG(cacheLine.iLockCount > 0, Fault(EClearDirtyNotLocked));
       
   819 	__ASSERT_ALWAYS(cacheLine.iClient == aClient, Fault(EExtendingUnownedCacheline));
       
   820 
       
   821 	TInt dirtySegments = cacheLine.iDirtySegments;
       
   822 	cacheLine.iDirtySegments = 0;
       
   823 	SetFilled(aClient, cacheLine, dirtySegments);
       
   824 	UnlockCacheLine(aClient, cacheLine);
       
   825 	}
       
   826 
       
   827 
       
   828 void CCacheManager::RemoveEmptySegments(CCacheClient* aClient, const TCacheLine& aCacheLine)
       
   829 	{
       
   830 	CacheLock();
       
   831 
       
   832 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
       
   833 	__CACHELINE_INVARIANT((cacheLine));
       
   834 
       
   835 	// has the cacheline been stolen ?
       
   836 	if (cacheLine.iClient != aClient)
       
   837 		{
       
   838 		__CACHE_PRINT(_L("CCacheManager::RemoveEmptySegments((), Cacheline Stolen ! !!!\n"));
       
   839 		CacheUnlock();
       
   840 		return;
       
   841 		}
       
   842 		
       
   843 	__ASSERT_DEBUG(cacheLine.iLockCount > 0, Fault(ERemovingEmptyUnlocked));
       
   844 
       
   845 	// Unlock any locked segments past the last filled segment
       
   846 	TInt filledSegmentCount = cacheLine.iFilledSegments;
       
   847 	TInt firstSegmentToUnlock;
       
   848 	TInt segmentsToUnlock;
       
   849 #ifdef __LOCK_ENTIRE_CACHELINE__
       
   850 	firstSegmentToUnlock = filledSegmentCount;
       
   851 	segmentsToUnlock = cacheLine.iAllocatedSegments - filledSegmentCount;
       
   852 #else
       
   853 	TInt firstLockedSegment = cacheLine.iLockedSegmentStart;
       
   854 	if (firstLockedSegment <= filledSegmentCount)
       
   855 		{
       
   856 		firstSegmentToUnlock = filledSegmentCount;
       
   857 		segmentsToUnlock = firstLockedSegment + cacheLine.iLockedSegmentCount - filledSegmentCount;
       
   858 		}
       
   859 	else
       
   860 		{
       
   861 		firstSegmentToUnlock = firstLockedSegment;
       
   862 		segmentsToUnlock = cacheLine.iLockedSegmentCount;
       
   863 		}
       
   864 #endif
       
   865 	TUint8* addrFirstSegmentToUnlock = 
       
   866 		cacheLine.iAddr + (firstSegmentToUnlock << KSegmentSizeLog2);
       
   867 	if (segmentsToUnlock > 0)
       
   868 		{
       
   869 		Unlock(addrFirstSegmentToUnlock, segmentsToUnlock);
       
   870 		cacheLine.iLockedSegmentCount = 
       
   871 			(TUint8) (cacheLine.iLockedSegmentCount - segmentsToUnlock);
       
   872 		}
       
   873 
       
   874 	// Decommit any segments past the last filled segment
       
   875 	Decommit(
       
   876 		cacheLine.iAddr + (filledSegmentCount << KSegmentSizeLog2), 
       
   877 		cacheLine.iAllocatedSegments - filledSegmentCount);
       
   878 	cacheLine.iAllocatedSegments = (TUint8) filledSegmentCount;
       
   879 
       
   880 	CacheUnlock();
       
   881 	}
       
   882 
       
   883 
       
   884 void CCacheManager::FreeCacheLine(TCacheLine& aCacheLine)
       
   885 	{
       
   886 	__ASSERT_DEBUG(iManagerLocked, Fault(EManagerNotLocked));
       
   887 	aCacheLine.iClient = NULL;
       
   888 	__ASSERT_ALWAYS( (aCacheLine.iLockCount == 0), Fault(EFreeingLockedCacheLine));
       
   889 	__ASSERT_ALWAYS( (aCacheLine.iDirtySegments == 0), Fault(EFreeingDirtyCacheLine));
       
   890 
       
   891 	Decommit(aCacheLine.iAddr, aCacheLine.iAllocatedSegments);
       
   892 	aCacheLine.iAllocatedSegments = 0;
       
   893 	aCacheLine.iFilledSegments = 0;
       
   894 	aCacheLine.iLockedSegmentStart = 0;
       
   895 	aCacheLine.iLockedSegmentCount = 0;
       
   896 
       
   897 	// Remove from used queue
       
   898 	TInt index = iUsedQueue.FindInAddressOrder(&aCacheLine);
       
   899 	__ASSERT_ALWAYS(index != KErrNotFound, Fault(ESegmentNotFound));
       
   900 	iUsedQueue.Remove(index);
       
   901 
       
   902 	// put back on free queue
       
   903 //	TInt r = iFreeQueue.Append(&aCacheLine);
       
   904 	TInt r = iFreeQueue.InsertInAddressOrder(&aCacheLine);
       
   905 	__ASSERT_ALWAYS(r == KErrNone, Fault(EAppendToFreeQueueFailed));
       
   906 
       
   907 	__CACHE_PRINT2(_L("CACHEMAN: FreeCacheLine, iFreeQueue %d iUsedQueue %d"), iFreeQueue.Count(), iUsedQueue.Count());
       
   908 	}
       
   909 
       
   910 
       
   911 #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
       
   912 void CCacheManager::DumpCacheLine(TCacheLine& aCacheLine)
       
   913 	{
       
   914 	RDebug::Print(_L("CACHEMAN: Cacheline client %08X addr %08X pos %d alloc %d filled %d dirty %d lock %d \tData: %02X %02X %02X %02X %02X %02X %02X %02X "), 
       
   915 		aCacheLine.iClient,
       
   916 		aCacheLine.iAddr,
       
   917 		I64LOW(aCacheLine.iPos),
       
   918 
       
   919 		aCacheLine.iAllocatedSegments,
       
   920 		aCacheLine.iFilledSegments,
       
   921 		aCacheLine.iDirtySegments,
       
   922 		aCacheLine.iLockCount,
       
   923 
       
   924 		aCacheLine.iAddr[0], 
       
   925 		aCacheLine.iAddr[1], 
       
   926 		aCacheLine.iAddr[2], 
       
   927 		aCacheLine.iAddr[3], 
       
   928 		aCacheLine.iAddr[4], 
       
   929 		aCacheLine.iAddr[5], 
       
   930 		aCacheLine.iAddr[6], 
       
   931 		aCacheLine.iAddr[7]
       
   932 		);
       
   933 	}
       
   934 
       
   935 void CCacheManager::DumpCache()
       
   936 	{
       
   937 	CacheLock();
       
   938 	
       
   939 	RPointerArray<CCacheClient> clients;
       
   940 
       
   941 	RDebug::Print(_L("**** CACHEMAN: CacheLines ****\n"));
       
   942 	TInt usedQueueSize = iUsedQueue.Count();
       
   943 	TInt n;
       
   944 	for (n=0; n<usedQueueSize; n++)
       
   945 		{
       
   946 		TCacheLine& cacheLine = *iUsedQueue[n];
       
   947 		DumpCacheLine(cacheLine);
       
   948 
       
   949 		clients.InsertInAddressOrder(cacheLine.iClient);
       
   950 		}
       
   951 
       
   952 	TInt clientCount = clients.Count();
       
   953 
       
   954 	for (n=0; n<clientCount; n++)
       
   955 		{
       
   956 		RDebug::Print(_L("**** CACHEMAN: CacheClient #%d ****\n"), n);
       
   957 		clients[n]->DumpCache();
       
   958 		}
       
   959 
       
   960 	clients.Close();
       
   961 
       
   962 	CacheUnlock();
       
   963 	}
       
   964 #endif
       
   965 
       
   966 
       
   967 
       
   968 
       
   969 TUint8* CCacheManager::Base()
       
   970 	{
       
   971 	return iChunk.Base();
       
   972 	}
       
   973 
       
   974 
       
   975 TInt CCacheManager::Lock(TUint8* const aAddr, TInt aSegmentCount)
       
   976 	{
       
   977 	TInt r = iChunk.Lock(aAddr-iBase, aSegmentCount << KSegmentSizeLog2);
       
   978 //RDebug::Print(_L("RChunk::Lock(%08X, %d) %d"), aAddr-iBase, aSegmentCount << KSegmentSizeLog2, r);
       
   979 	__ASSERT_DEBUG(r == KErrNone || r == KErrNoMemory || r == KErrNotFound, Fault(EUnexpectedLockFailure));
       
   980 
       
   981 	__CACHE_PRINT3(_L("CACHEMAN: LOCK %08X %d %d"), aAddr, aSegmentCount, r);
       
   982 
       
   983 #ifdef  __SIMULATE_LOCK_FAILURES__
       
   984 	if (SimulatedFailure(iLockFailureCount))
       
   985 		{
       
   986 		__CACHE_PRINT(_L("CACHEMAN: simulating lock failure"));
       
   987 		r = KErrNotFound;
       
   988 		}
       
   989 #endif
       
   990 
       
   991 	if (r == KErrNone)
       
   992 		{
       
   993 		iLockedSegmentCount+= aSegmentCount;
       
   994 		}
       
   995 	else
       
   996 		{
       
   997 		__CACHE_PRINT(_L("CACHEMAN: LOCK FAILED"));
       
   998 #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
       
   999 		iStats.iLockFailureCount++;
       
  1000 #endif
       
  1001 		}
       
  1002 
       
  1003 	return r;
       
  1004 	}
       
  1005 
       
  1006 TInt CCacheManager::Unlock(TUint8* const aAddr, TInt aSegmentCount)
       
  1007 	{
       
  1008 	TInt r = iChunk.Unlock(aAddr-iBase, aSegmentCount << KSegmentSizeLog2);
       
  1009 //RDebug::Print(_L("RChunk::Unlock(%08X, %d) %d"), aAddr-iBase, aSegmentCount << KSegmentSizeLog2, r);
       
  1010 
       
  1011 	__CACHE_PRINT3(_L("CACHEMAN: UNLOCK %08X %d %d"), aAddr, aSegmentCount, r);
       
  1012 	if (r == KErrNone)
       
  1013 		{
       
  1014 		iLockedSegmentCount-= aSegmentCount;
       
  1015 		}
       
  1016 	else
       
  1017 		{
       
  1018 		__CACHE_PRINT(_L("CACHEMAN: UNLOCK FAILED"));
       
  1019 		}
       
  1020 
       
  1021 	return r;
       
  1022 	}
       
  1023 
       
  1024 TInt CCacheManager::Commit(TUint8* const aAddr, TInt aSegmentCount)
       
  1025 	{
       
  1026 #ifdef  __SIMULATE_LOCK_FAILURES__
       
  1027 	if (SimulatedFailure(iCommitFailureCount))
       
  1028 		{
       
  1029 		__CACHE_PRINT(_L("CACHEMAN: simulating commit failure "));
       
  1030 		return KErrNoMemory;
       
  1031 		}
       
  1032 #endif
       
  1033 
       
  1034 	TInt r = iChunk.Commit(aAddr-iBase, aSegmentCount << KSegmentSizeLog2);
       
  1035 //RDebug::Print(_L("RChunk::Commit(%08X, %d) %d, "), aAddr-iBase, aSegmentCount << KSegmentSizeLog2, r);
       
  1036 	
       
  1037 	__CACHE_PRINT3(_L("CACHEMAN: COMMIT: %08X %d %d, "), aAddr, aSegmentCount, r);
       
  1038 	if (r == KErrNone)
       
  1039 		{
       
  1040 		iLockedSegmentCount+= aSegmentCount;
       
  1041 #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
       
  1042 		iStats.iAllocatedSegmentCount+= aSegmentCount;
       
  1043 #endif
       
  1044 		}
       
  1045 	else
       
  1046 		{
       
  1047 		__CACHE_PRINT(_L("CACHEMAN: COMMIT FAILED"));
       
  1048 #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
       
  1049 		iStats.iCommitFailureCount++;
       
  1050 #endif
       
  1051 		}
       
  1052 
       
  1053 
       
  1054 	__ASSERT_DEBUG(r == KErrNone || r == KErrNoMemory, Fault(EUnexpectedCommitFailure));
       
  1055 
       
  1056 	return r;
       
  1057 	}
       
  1058 
       
  1059 TInt CCacheManager::Decommit(TUint8* const aAddr, TInt aSegmentCount)
       
  1060 	{
       
  1061 	TInt r = iChunk.Decommit(aAddr-iBase, aSegmentCount << KSegmentSizeLog2);
       
  1062 //RDebug::Print(_L("RChunk::Decommit(%08X, %d), %d"), aAddr-iBase, aSegmentCount << KSegmentSizeLog2, r);
       
  1063 
       
  1064 	__CACHE_PRINT3(_L("CACHEMAN: DECOMMIT: %08X %d %d, "), aAddr, aSegmentCount, r);
       
  1065 	if (r == KErrNone)
       
  1066 		{
       
  1067 #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
       
  1068 		iStats.iAllocatedSegmentCount-= aSegmentCount;
       
  1069 #endif
       
  1070 		}
       
  1071 	else
       
  1072 		{
       
  1073 		__CACHE_PRINT(_L("CACHEMAN: DECOMMIT FAILED"));
       
  1074 		}
       
  1075 
       
  1076 	return r;
       
  1077 	}
       
  1078 
       
  1079 #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
       
  1080 
       
  1081 void CCacheManager::SimulateLockFailureMode(TBool aEnable)
       
  1082 	{
       
  1083 	iSimulateLockFailureMode = aEnable;
       
  1084 __CACHE_PRINT1(_L("CACHEMAN: SimulateLockFailureMode: %d, "), iSimulateLockFailureMode);
       
  1085 	}
       
  1086 
       
  1087 void CCacheManager::AllocateMaxSegments(TBool aEnable)
       
  1088 	{
       
  1089 	iAllocateMaxSegments = aEnable;
       
  1090 __CACHE_PRINT1(_L("CACHEMAN: iAllocateMaxSegments: %d, "), iAllocateMaxSegments);
       
  1091 	}
       
  1092 
       
  1093 TBool CCacheManager::AllocateMaxSegments()
       
  1094 	{
       
  1095 	return iAllocateMaxSegments;
       
  1096 	}
       
  1097 
       
  1098 void CCacheManager::SimulateWriteFailure()
       
  1099 	{
       
  1100 	iSimulateWriteFailure = ETrue;
       
  1101 	}
       
  1102 
       
  1103 TBool CCacheManager::SimulateWriteFailureEnabled()
       
  1104 	{
       
  1105 	TBool b = iSimulateWriteFailure;
       
  1106 	iSimulateWriteFailure = EFalse;
       
  1107 	return b;
       
  1108 	}
       
  1109 
       
  1110 TBool CCacheManager::SimulatedFailure(TInt& aFailureCount)
       
  1111 	{
       
  1112 #ifdef  __SIMULATE_LOCK_FAILURES__
       
  1113 	if (iSimulateLockFailureMode)
       
  1114 		{
       
  1115 #if defined  (__RAMDOM_LOCK_FAILURES__)
       
  1116 		static TInt FailCount = 15;
       
  1117 		if (++aFailureCount >= FailCount)
       
  1118 #elif defined (__PSEUDO_RANDOM_FAILURES__)
       
  1119 		const TInt FailCounts[] = {15,2,0,21,1,12,24};
       
  1120 		const TInt FailCountSize = sizeof(FailCounts) / sizeof(TInt);
       
  1121 		static TInt FailCountIndex = 0; 
       
  1122 		if (++aFailureCount >= FailCounts[FailCountIndex])
       
  1123 #else
       
  1124 		const TInt KFailCount = 15;
       
  1125 		if (++aFailureCount >= KFailCount)
       
  1126 #endif
       
  1127 			{
       
  1128 			aFailureCount = 0;
       
  1129 #if defined (__RAMDOM_LOCK_FAILURES__)
       
  1130 			FailCount = Math::Random() & 0x1F;
       
  1131 			__CACHE_PRINT1(_L("FailCount %d"), FailCount);
       
  1132 #endif
       
  1133 
       
  1134 #if defined (__PSEUDO_RANDOM_FAILURES__)
       
  1135 			FailCountIndex = (FailCountIndex +1) % FailCountSize ;
       
  1136 			__CACHE_PRINT1(_L("FailCount %d"), FailCounts[FailCountIndex]);
       
  1137 #endif
       
  1138 
       
  1139 			return ETrue;
       
  1140 			}
       
  1141 		}
       
  1142 #endif
       
  1143 	return EFalse;
       
  1144 	}
       
  1145 #endif	// defined(_DEBUG) || defined(_DEBUG_RELEASE)
       
  1146 
       
  1147 //************************************
       
  1148 // TGlobalFileCacheSettings
       
  1149 //************************************
       
  1150 
       
  1151 //TGlobalCacheFlags TGlobalFileCacheSettings::iFlags = TGlobalCacheFlags(ECacheEnabled);
       
  1152 TInt32 TGlobalFileCacheSettings::iCacheSize	= KDefaultGlobalCacheSize << KByteToByteShift;
       
  1153 TInt32 TGlobalFileCacheSettings::iMaxLockedSize	= KDefaultGlobalCacheMaxLockedSize << KByteToByteShift;
       
  1154 TInt32 TGlobalFileCacheSettings::iLowMemoryThreshold = KDefaultLowMemoryThreshold;
       
  1155 TBool TGlobalFileCacheSettings::iEnabled	= KDefaultGlobalCacheEnabled; 
       
  1156 
       
  1157 _LIT8(KLitSectionNameFileCache,"FileCache");
       
  1158 
       
  1159 void TGlobalFileCacheSettings::ReadPropertiesFile()
       
  1160 	{
       
  1161 	F32Properties::GetBool(KLitSectionNameFileCache, _L8("GlobalCacheEnabled"), iEnabled);
       
  1162 	
       
  1163 	// Get size of cache in kilobytes
       
  1164 	TInt32 cacheSizeInKBytes;
       
  1165 	if (F32Properties::GetInt(KLitSectionNameFileCache, _L8("GlobalCacheSize"), cacheSizeInKBytes))
       
  1166 		iCacheSize = cacheSizeInKBytes << KByteToByteShift;
       
  1167 
       
  1168 	// Get maximum amount of locked data i.e data unavailable for paging
       
  1169 	TInt32 maxLockedSize;
       
  1170 	if (F32Properties::GetInt(KLitSectionNameFileCache, _L8("GlobalCacheMaxLockedSize"), maxLockedSize))
       
  1171 		iMaxLockedSize = maxLockedSize << KByteToByteShift;
       
  1172 
       
  1173 	// Get low memory threshold
       
  1174 	TInt32 lowMemoryThreshold;
       
  1175 	if (F32Properties::GetInt(KLitSectionNameFileCache, _L8("LowMemoryThreshold"), lowMemoryThreshold))
       
  1176 		iLowMemoryThreshold = lowMemoryThreshold;
       
  1177 
       
  1178 	}
       
  1179 
       
  1180 
       
  1181 TBool TGlobalFileCacheSettings::Enabled()
       
  1182 	{
       
  1183 	return iEnabled;
       
  1184 	}
       
  1185 
       
  1186 TInt TGlobalFileCacheSettings::CacheSize()
       
  1187 	{
       
  1188 	return iCacheSize;
       
  1189 	}
       
  1190 TInt TGlobalFileCacheSettings::MaxLockedSize()
       
  1191 	{
       
  1192 	return iMaxLockedSize;
       
  1193 	}
       
  1194 
       
  1195 TInt TGlobalFileCacheSettings::LowMemoryThreshold()
       
  1196 	{
       
  1197 	return iLowMemoryThreshold;
       
  1198 	}